Non-functioning pituitary adenoma: an incidental finding or a stroke mimic?
V Kolovou, R W Carroll, A P Goldstone
Imperial Centre for Endocrinology.
A 49 year old male with a history of ischaemic heart disease and previous angioplasty, type 2 diabetes mellitus on insulin therapy, hypothyroidism and hypercholesterolaemia presented to the Emergency Department with transient left arm and face sensory disturbance. He described pins and needles across the left face and trunk from the midline, and complete left arm and leg involvement. The symptoms persisted for 36 hours but were intermittent in nature. Neurological examination was normal including cranial nerves and visual fields. CT head revealed evidence of cerebrovascular disease with an established left cerebellar hemisphere infarct. Additionally, a large pituitary macroadenoma was noted with significant suprasellar extension. Retrospective questioning revealed erectile dysfunction noted over many years and reduced libido.
Routine admission blood tests were unremarkable aside from a low sodium level of 132mmol/L. Baseline 09:00 bloods showed low cortisol 66 nmol/L, normal ACTH 21.9 ng/L, testosterone 12.3 nmol/L, LH 2.2 IU/L, FSH 4.5 IU/L, normal thyroid function tests, and a raised prolactin 1482mU/L (normal <375) although approximately 50% was due to macroprolactin.
The patient was discharged on hydrocortisone 10mg on waking, 10mg at 12:00 and 5mg at 17:00 and subsequently had a satisfactory day curve on this dose. An outpatient MRI of the pituitary confirmed a macroadenoma with which extends laterally into the cavernous sinus on both sides, and displacing the optic chiasm superiorly. Outpatient echocardiogram, carotid Doppler studies and 24 hour tape are awaited in view of his neurological symptoms.
This patient had a radiological finding of a probably incidental pituitary macroadenoma since any relation with his limb neurological symptoms is unclear. Biochemical testing found secondary cortisol insufficiency and mild hyperprolactinaemia (plus macroprolactin) but no hypogonadism. It is currently unknown whether the previously diagnosed hypothyroidism was primary or secondary since a pre-treatment TSH is not yet available. Dynamic assessment of GH reserve is awaited.
We would suggest the following as points of discussion:
In the context of normal visual function and given the radiological findings, is there an indication for surgery now or a conservative approach with follow-up scans and repeat visual field testing?
If surgery is recommended what can the patient be advised about long term pituitary function? What is the cause of his hyperprolactinaemia?
Is there a role for any medical approach? How should his hormonal deficiencies best be managed?